JPH0678411B2 - Curable resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a curable polymaleimide resin composition. In particular, the present invention provides a curable resin composition which is excellent in low-temperature curability and whose cured product is excellent in heat resistance, mechanical properties, and particularly toughness.

[Prior Art] Curable resins are widely used in paints, insulating materials, composite structural materials and the like as adhesives, casting, coating, impregnation, lamination, molding compounds and the like. However,
In recent years, its applications have been diversified, and conventionally known curable resins cannot be satisfied depending on the use environment and use conditions. Of these, in particular, it is not sufficient for use under high temperature, and development in this aspect is desired.

Among them, the polyimide resin is one of the most excellent materials, and various developments have been made. For example, JP-A-62
-53319 discloses compositions of polymaleimide compounds and reactive oligomers having alkenyl ethers at the ends of the molecule. However, this resin composition has a high curing temperature and a long curing time, and in terms of workability including these, it cannot be said that it is more advantageous than existing general-purpose curable resins. This can be said even in the most typical compositions that are conventionally known, such as a combination of bismaleimide and an aromatic amine, a combination of bismaleimide, an aromatic amine and an epoxy resin, and heat resistance,
No material having excellent mechanical properties and low temperature curability has been provided.

[Problems to be Solved by the Invention]

In view of these circumstances, some of the inventors of the present invention have been keenly researched to provide a polyimide resin composition having a low curing temperature, a short curing time, and excellent heat resistance and thermal stability, and excellent mechanical properties. As a result of stacking, maleimide compounds and methylhydroquinone divinylbenzyl ether are representative.
Curable resin composition comprising a polyhydric phenol divinylbenzyl ether compound having one or more substituents, and curing comprising a maleimide compound and a polyhydric naphthol divinylbenzyl ether compound represented by 1,4 naphthalenedivinylbenzyl ether A reactive resin composition,
Although previously proposed (Japanese Patent Application No. 1-153896 (Japanese Patent Application Laid-Open No. 3-20312)
No.), Japanese Patent Application No. 63-241231 (JP-A-2-88609)), both of which show excellent heat resistance, but since the cured product tends to be a little brittle, improvement in toughness is required. Was there.

As a result of further research, the present inventors have improved the toughness of the vinyl benzyl ether compound in which a molecular chain is partially extended by using an epoxy resin without impairing the heat resistance, and a polyimide having further excellent physical properties. The present invention has been achieved by finding that a resin composition can be obtained.

[Means for Solving the Problems]

That is, the present invention uses a compound (A) having one or more maleimide groups in the molecule, and 0.05 equivalent to 0.5 equivalent of an epoxy resin for 1 equivalent of polyhydric phenol or polyhydric naphthol to form a molecular chain. A curable composition comprising a compound (B) having two or more vinylbenzyl ether groups bonded to an extended benzene nucleus or a naphthalene nucleus, which can be cured at a relatively low temperature as in the previous application and has a short curing time. Moreover, the cured product not only exhibits excellent thermal stability, but also provides a curable composition having significantly improved toughness.

The details of the present invention are shown below.

The compound (A) having a maleimide group used in the present invention means N, N'phenylene bismaleimide, N, N'xylene bismaleimide, N, N 'tolylene bismaleimide, N, N' diphenylmethane bismaleimide, N , N ′ diphenyl ether bismaleimide, N, N ′ diphenyl sulfone bismaleimide, N, N ′ diphenylmethane bismethyl maleimide, N, N ′ diphenyl ether bismethyl maleimide,
N, N ′ hydrogenated phenylmethane bismaleimide, and further has a maleimide group as an adduct of these bismaleimides with amino compounds such as diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl ether, and amino compounds modified with epoxy resin. A compound can be illustrated. Examples of monofunctional maleimides include aromatic maleimides represented by phenylmaleimide, alkyl maleimides represented by lauryl maleimide, and alicyclic maleimides represented by cyclohexylmaleimide.

Two or more vinylbenzyl ether groups bonded to a benzene nucleus or a naphthalene nucleus whose molecular chain is extended by using 0.05 equivalent to 0.5 equivalent of an epoxy resin with respect to 1 equivalent of polyphenol or polynaphthol used in the present invention. The compound (A) (hereinafter referred to as vinyl benzyl ether compound) having at least 2 hydroxyl groups directly bonded to benzene
A compound having more than one, for example, 2,3-dioxytoluene,
3,4-dioxytoluene, 4-ter-butylcatechol, cresorcin, orcin, β-orcin, m-xylorcine,
4-n-hexylresorcin, 2-methylhalide roquinone,
Ter-butylhydroquinone, 2,5-ter-acylhydroquinone, 2,5-diethoxyhydroquinone, 2,3,6-trimethylhydroquinone, pyrogallol, pyrogallol-2-methyl ether, pyrogallol monoacetate, 1,3,5-
A compound having at least two hydroxyl groups directly linked to polyphenols such as trioxybenzene or naphthalene, for example, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxy. Naphthalene, 1,6-dihydroxynaphthalene, 1,7-
Dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,2,3-trihydroxynaphthalene, 1,2,4-trihydroxynaphthalene , 1,4,5-trihydroxynaphthalene, 1,2,3,4-tetrahydroxynaphthalene, 1,2,3,4,5,8-hexahydroxynaphthalene, etc. 0.05 equivalent to 0.5 equivalent per 1 equivalent Epoxy resin, for example, a bis-based epoxy resin having an epoxy equivalent of 170 to 500, a novolac type epoxy resin having an epoxy equivalent of 190 to 250, a naphthalene skeleton type epoxy resin having an epoxy equivalent of 140 to 200, and an aromatic amine type epoxy having an epoxy equivalent of 100 to 200. After extending the molecular chain of the resin or the like in the presence of an amine catalyst such as triethylamine, if necessary, using a solvent such as dioxane or dimethyl sulfoxide, the halomethylstyrene example For example, it can be easily synthesized from chloromethylstyrene by dehydrochlorination with caustic potash or caustic soda using a solvent such as alcohol, dioxane or dimethylsulfoxide.

When the molecular chain is extended with an epoxy resin, a vinylbenzyl compound in which the number of equivalents of the epoxy resin is 0.05 equivalent or less relative to 1 equivalent of polyvalent phenol or polyvalent naphthol,
A toughness effect cannot be obtained. On the other hand, when it is 0.5 equivalent or more, not only the viscosity is too high but the workability is deteriorated, but also the heat resistance is lowered.

The component ratio in the composition of the maleimide compound (A) and the vinyl benzyl ether compound (B) in the present invention can be widely varied depending on the purpose of use, but when represented by the unsaturated group equivalent ratio, A / B = 100/30 to 1/100,
More preferably, it is 100/50 to 1/30, and in the case of these ranges, it easily heat-cures without intentionally adding a radical initiator necessary for curing, and each heat-curing alone. The reaction proceeds at a much lower temperature and in a shorter time than Further, in the case of these ranges, the thermal decomposition start temperature in air is high and the decomposition weight loss is small.

In the curable composition of the present invention, in addition to the components (A) and (B), other known monomers such as styrene, vinyltoluene, allylphenol, allyloxybenzene, diallylphthalate and acrylic acid are used. Ester, methacrylic acid ester, vinylpyrrolidone, monofunctional maleimide compounds such as phenylmaleimide and alkylmaleimide, etc. can be blended within a range not departing from the concept of the present invention. It goes without saying that hydroquinone, benzoquinone, copper salts, tetramethylthiuram compounds, nitrosophenylhydroxyl compounds, and other publicly known substances for the purpose of adjusting the curing can be added, and radical initiators can be added for promoting the curing. Nor.

The curable composition of the present invention is a kneader, a blender, a roll, or the like, as a molding material or a composite material by blending various other fillers and reinforcing fibers, or as a varnish, a paint, or an adhesive dissolved in a solvent. Further, it is possible to impregnate glass fibers, carbon fibers, aromatic polyamide fibers, silicon carbide fibers, and alumina fibers, which are reinforcing fibers, into a molding material or structural material useful as a prepreg and as a filament winding.

Next, reference examples and examples will be shown in order to explain the present invention in detail, but these do not limit the scope of the present invention. Unless otherwise specified, the parts in the examples are parts by weight.

Reference Example 1 Synthesis of methylhydroquinone divinylbenzin ether whose molecular chain was extended with a bisphenol A type epoxy resin 62 parts of 2-methylhydroquinone (1.0 equivalent) and 47.3 parts (0.25 equivalent) of a bis A type epoxy resin with an epoxy equivalent of 189, reaction Charge 0.11 part of triethylamine as a catalyst and adjust the temperature.
After raising the temperature to 150 ° C and reacting for about 1 hour, 120 parts of dimethyl sulfoxide, 42.1 parts of potassium hydroxide (0.75 equivalents), 30 parts of water
Dissolved in 1 part and commercial chloromethylstyrene 114.4
Part (0.75 equivalents) dissolved in 25 parts of dimethyl sulfoxide was added dropwise at 70-80 ° C over 1 hour, and then 70-80 ° C.
The reaction was continued for 2 hours. Next, add a large excess of water to the system,
After stirring, an oily substance was extracted with benzene. 5% benzene layer
It was washed with caustic potash and washed repeatedly with water until the pH of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The reaction product was an oily substance, and the yield was 94% after removal of benzene, and it was soluble in various organic solvents (hereinafter, abbreviated as 0.25 equivalent bisA epoxy-modified MHQDVBE).

Reference example 2 Synthesis of naphthalene divinyl benzyl ether whose molecular chain was extended with naphthalene skeleton epoxy resin 80 parts of 1,4 dihydroxynaphthalene (1.0 equivalent) and 37 parts of 1,6 diglycidyloxynaphthalene (0.25 equivalent) were added to 100 parts of dimethyl sulfoxide. Dissolved in 1 part and added with 0.12 part of triethylamine as a reaction catalyst, the temperature was raised to 130 ° C., and after the reaction for about 2 hours, 50 parts of dimethyl sulfoxide and potassium hydroxide
42.1 parts (0.75 equivalents), dissolved in 30 parts of water and 114.4 parts (0.75 equivalents) of commercially available chloromethylstyrene dissolved in 25 parts of dimethyl sulfoxide were added dropwise at 70 to 80 ° C over 1 hour, and further 70 The reaction was continued for 2 hours at -80 ° C. Next, a large excess of water was added to the system, and after stirring, an oily substance was extracted with benzene. The benzene layer was washed with 5% caustic potash, washed repeatedly with water until the pH of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The reaction product was an oil, and the yield was 93%.
It was soluble in various organic solvents (hereinafter abbreviated as 0.25 equivalents naphthalene type epoxy modified 1.4NDVBE).

Reference example 3 ter- whose molecular chain is extended with an aromatic amine type epoxy resin
Synthesis of butyl hydroquinone divinyl benzyl ether 83 parts ter-butyl hydroquinone (1.0 equivalent) and 11.5 parts tetraglycidyl diaminodiphenylmethane (0.1 equivalent)
Was dissolved in 100 parts of dimethyl sulfoxide, 0.1 part of triethylamine was added as a reaction catalyst, the temperature was raised to 130 ° C., and the reaction was continued for about 2 hours. Then, 50 parts of dimethyl sulfoxide, 50.5 parts of potassium hydroxide (0.9 equivalents), in 30 parts of water Dissolved in 100 parts of commercially available chloromethylstyrene (0.9 equivalents) dissolved in 30 parts of dimethyl sulfoxide was added dropwise at 70 to 80 ° C over 1 hour, and the reaction was continued at 70 to 80 ° C for 2 hours. .
Next, a large excess of water was added to the system, and after stirring, an oily substance was extracted with benzene. The benzene layer was washed with 5% caustic potash, washed repeatedly with water until the pH of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The reaction product was an oily substance with a yield of 93% and was soluble in various organic solvents (hereinafter, 0.1 equivalent TGD).
It is abbreviated as DM-modified t-BHQDVBE). Epoxy equivalent 189 Bis type epoxy resin 0.1 equivalent modified MHQ DVBE, tetraglycidyl diaminodiphenylmethane 0.1 equivalent modified MHQ
DVBE, epoxy equivalent 189 bis type epoxy 0.25 equivalent modified 1,4
Naphthalene divinyl benzyl ether was synthesized (below 0.1 eq each bis A epoxy modified MHQDVBE, 0.1 eq T
GDDM modified MHQDVBE, 0.25 equivalent bis A epoxy modified 1,4NDVB
Abbreviated as E).

Table 1 shows the properties of each divinylbenzyl ether modified with an epoxy resin.

Reference Example 4 Synthesis of diaminodiphenylmethane modified bismaleimide by reaction of bismaleimide and diaminodiphenylmethane N, N′-diphenylmethane bismaleimide 358 parts (1.0 mol) and diaminodiphenylmethane 99 parts (0.5 mol) were sufficiently pulverized and mixed by a ball mill. 1 in a container at 170 ℃
Melting and stirring were performed for 0 minutes, and the container was immediately cooled with water to obtain a solid product. This reaction product was soluble in solvents such as N-methylpyrrolidone and dimethylformamide, and was also soluble in low boiling solvents such as acetone and methyl ethyl ketone (hereinafter abbreviated as DDM modified BMI).

Reference Example 5 Methylhydroquinone divinylbenzyl ether (MHQD
VBE) 2-methylhydroquinone 62 parts (1.0 equivalent), potassium hydroxide 56.1 parts (1.0 equivalent) to dimethyl sulfoxide 120 parts,
Dissolves in 30 parts of water and contains commercially available chloromethylstyrene
A solution prepared by dissolving 152.5 parts (1.0 equivalent) in 50 parts of dimethyl sulfoxide was added dropwise at 70 ° C over 1 hour, and then at 70 ° C for 2 hours.
The reaction continued for an hour. Next, a large excess of water was added to the system, and after stirring, water-dimethyl sulfoxide was removed and an oily substance was extracted with benzene. The benzene layer was washed with 5% potassium hydroxide and washed with water repeatedly until the pH of the aqueous layer reached 7, and the benzene layer was dried with anhydrous sodium sulfate. The reaction product was an oil, and the yield was 98% after removal of benzene, and it was soluble in various organic solvents (hereinafter abbreviated as MHQDVBE).

Example 1 6 kinds of divinylbenzyl ether (0.25
Equivalent bis A epoxy modified MHQDVBE, 0.25 equivalent naphthalene type epoxy modified 1,4NDVBE, 0.1 equivalent TGDDM modified t-BHQDVB
E, 0.1 equivalent bis A epoxy modified MHQDVBE, 0.1 equivalent TGDDM
Modified MHQDVBE, 0.25 equivalent bis A epoxy modified 1.4NDVBE)
Samples were prepared by mixing 100 parts of each of the above with 100 parts of diphenylmethane bismaleimide (manufactured by Ciba-Geigy). These were placed on a hot plate at 120 ° C and examined for gelation. For comparison, the results of the same test conducted for VBE and bismaleimide are summarized in Table-2.

Next, each composition was molded at 120 ° C for 30 minutes, and after demolding, 2
The thermal decomposition initiation temperature in air was measured for the material which had been cured at 50 ° C for an hour, and the results are shown in Table-3.

Example 2 0.25 equivalent bis A epoxy modified MHQDVB synthesized in Reference Example
E, 0.25 equivalent of naphthalene type epoxy modified 1.4NDVBE, 0.1 equivalent of TGDDM modified t-BHQDVBE to 100 parts of each, DDM modified BMI or phenylmaleimide 10 synthesized in Reference Example 4
A sample containing 0 parts was molded at 120 ° C for 30 minutes, and after demolding, continue to 25
The thermal decomposition initiation temperature in air was measured for the one cured after 5 hours at 0 ° C., and the results are shown in Table 4.

Reference Example 3 6 kinds of divinyl benzyl ether synthesized in Reference Example [0.25
Equivalent bis A epoxy modified MHQDVBE (a), 0.25 equivalent naphthalene type epoxy modified 1,4NDVBE (b), 0.1 equivalent TGDDM modified t-BHQDVBE (c), 0.1 equivalent bis A epoxy modified MHQDVB
E (d), 0.1 equivalent of TGDDM-modified MHQDVBE (e), 0.25 equivalent of bis-A epoxy-modified 1,4NDVBE (f)], 100 parts of diphenylmethane bismaleimide (Ciba-Geigy) or a reference example DDM modified BMI synthesized in 4
A sample containing 100 parts of the above was molded at 120 ° C for 30 minutes, demolded, and subsequently cured at 250 ° C for 5 hours. JIS K 6911
The flexural strength, flexural elastic viscosity, and flexural maximum flexure were measured at room temperature and during hot work, and the results are shown in Table-5.

Comparative Example 0.25 equivalent bis A epoxy modified MHQBVBE in Example 3
In place of using MHQDVBE synthesized in Reference Example 5,
Bending strength characteristics of the cast cured product were measured in the same manner as in Example 3 and shown in Table 6.

[Effects of the Invention] The curable resin composition according to the present invention has excellent curability due to the above-mentioned constitution, and its cured product has excellent heat resistance and excellent mechanical strength, particularly toughness. As shown, it is widely available in industry as an adhesive, casting, coating, impregnating, laminating compound, or as a paint, insulating material or composite structural material.

Claims (1)

[Claims] 1. A compound (A) having one or more maleimide groups in the molecule and 1 equivalent of polyhydric phenol or polyhydric naphthol,
A curable resin composition comprising a compound (B) having two or more vinylbenzyl ether groups bonded to a benzene nucleus or a naphthalene nucleus whose molecular chain is extended by using 0.05 to 0.5 equivalent of an epoxy resin.